Track structure of the rapid track transit

ABSTRACT

A guideway structure for high-speed track-bound transportation composed of two or more than two girder-segments. The structure of the guideway is characteristic of: At the intermediate positions on the girder top and the girder bottom of the connecting ends of the said girder-segments are all disposed the pre-embedded steel elements and some anchoring nails used for ensuring the pre-embedded steel elements to be reliably connected with the concrete of girder-segments, after the relevant connecting ends of the two adjacent girder-segments are placed closely, they may be connected together to form a two-span quasi-continuous girder by tightening a plurality of bolts through their respective through hole on the connecting elements and on the pre-embedded elements.

FIELD OF THE INVENTION

[0001] The invention relates to track-bound transportation, namely amodern high-speed track-bound transportation, and especially relates toa guideway structure suitable for high-speed magnetic levitation(maglev) transportation.

BACKGROUND OF THE INVENTION

[0002] The whole track is formed by connecting the guideway girders oneby one; each of those is placed across two adjacent supporting columns.For the modern high speed track-bound transportation system such as themaglev train, etc. it requires that the guideway must be of extremelyhigh accuracy, the deformation and the deflection of the guideway due tothe influence of the factors of temperature difference, dynamic load andetc. must be controlled within a very small range, when the train is inhigh speed running. In the case of the traditional bridges, there is nodifficulty to solve the problems of deflection and the hogging back ofthe girders caused by the temperature difference or dynamic load, but inthe case of the guidelway for the running of the modern high-speedtrack-bound vehicle, especially for the running of the maglev train,these small deformations caused by the temperature difference or dynamicload will influence the high-speed running of the train.

[0003] Through calculation it is known that in comparison of thestructural functions of a continuous girder and two simply supportedgirders of the same section, the former has the superiority in thecontrol of the deformation caused by the temperature difference and thedynamic load. But the guideway with continuous girder structuregenerally adopts such a construction mode, i.e. the girders have to bepre-fabricated in factory and then erected on site. Because the size andthe weight of the continuous girder itself are too big, and in themeantime because the multi-span continuous girder belongs to amulti-point supported external hyper-static structure, in the process oftransporting, lifting and installing the multi-span continuous girdermust be kept in a multi-point supporting state from the beginning to theend, as well as the dislocations of any supporting point also must becontrolled within a small range in order to ensure the safety of themulti-span continuous girder itself. If not, the damages of multi-spancontinuous girder will occur easily in the whole process of the guidewayconstruction. Therefore in the process of the construction not only aparallel road of high class has to be built along the guideway which isspecially used for transporting the multi-span continuous girder,simultaneously the special carrier for the multi-point supported girdersand the crane specially for the multi-point synchronous lifting must beavailable. These will bring many difficulties in fabrication,processing, transportation, installation and positioning, as a result,the cost of fabrication and construction will greatly increase.

[0004] Under the action of temperature difference, all the supportreaction forces of continuous girder at intermediate column, whetheralong vertical direction or along horizontal direction, generally arequite greater than those of simply-supported girder. From the view pointof the viaduct foundation structure, it has a better function forresisting vertical reaction force, the increase of the vertical reactionforce is insensitive to the construction cost of the lower foundation,but its function for resisting horizontal reaction force always ispoorer. Each time, even a small increase of the horizontal reactionforce caused by the upper structure will make a great increase of thematerial consumption for the lower foundation. It is especially so inthe case of soft soil foundation.

[0005] The Germany Patent DE19936756 disclosed a method to connectseveral simply-supported type girders to be a continuous girder as shownin FIG. 1. The method of Patent DE19936756 yet is to connect thesesimply-supported type girders to be an entirely continuous girderwhether observing it along vertical direction or observing it alonghorizontal direction, namely it is connected to be a truly continuousgirder. Thus, such a structural mode cannot overcome the disadvantagethat in this case the horizontal support reaction force of thecontinuous girder at the intermediate column is too big, so it is unableto achieve the objective of decreasing the construction cost of thelower foundation.

[0006] Additionally, in Patent DE19936756 a mode of embeddedguide-screws and toothed-structure is used for connecting andpositioning two simply-supported girder-segments. Because theguide-screw and the toothed structure all are embedded and positionedbefore pouring concrete or formed during pouring concrete, even thoughtwo adjacent segments of girder are poured at the same time, yet it canonly be ensured that the positions relative to the concrete structureelements between two adjacent girder-segments are aligned. But for thestructure of maglev guideway line or other high-speed track-boundtransportation, the accurate positioning of space position means thecontinuous alignment of the phase positions among all the functionalsurfaces of the track. Moreover, the dimensions and positions of thesefunctional surfaces are determined by the successive machining and theaccurate assembly carried out after the pre-fabrication of the concretemain body of guideway girder has been completed. In this case, thedimensions of original guideway girder structural element had beencorrected by reducing or complementarily adding material, thus thedimensions and positions of finally-finished functional surfaces of theguideway girder are far different from those of the original concretegirder-segment structural element. Hence the method of using embeddedguide-screws and toothed structures of Patent DE19936756, in fact,cannot achieve the objective for accurately positioning two adjacentgirder-segments.

CONTENTS OF THE INVENTION

[0007] The technical problem need to be solved by the invention is toovercome the aforesaid existing technical deficiencies and to provide aguidelway structure suitable for the high-speed track-boundtransportation. To be specific, connecting a plurality ofsimply-supported girder-segments together to be a multi-spanquasi-continuous girder aims to utilize fully the advantage of thecontinuous girder that the deformation caused by temperature differenceand dynamic load may be controlled to be smaller, and that thedifficulties in pre-fabricating, processing, transporting and installinga bigger and heavier continuous girder may be conquered.

[0008] The conception of the invention is that every girder-segment laidacross two adjacent supporting columns of the guideway is fabricated,processed, transported, installed and accurately positioned as asimply-supported girder, then these girder-segments across two spans (ora plurality of spans) are connected together to be a quasi-continuousgirder, which has a structure mode approximate to a continuous girderwith a bending-rigidity as large as possible in vertical plane (i.e. adirection around Y-axis) and has a structure mode approximate to aquasi-continuous girder by a structure mode to hinge-joint many of two-or multi-span simply-supported girder-segments together one by one andwith a bending-rigidity as small as possible along horizontal direction(i.e. a direction around Z-axis).

[0009] The Technical Solution is as Follows:

[0010] A track structure for high-speed track-bound transportationinclusive of two or more than two girder-segments is characteristic ofthe following:

[0011] In the laterally intermediate portions of girder top and girderbottom at the connected ends of girder-segment are disposed the steelpre-embedded elements and many anchoring nails used for ensuring thepre-embedded elements to be reliably connected with the concrete of thegirder-segment. When the connecting end of one girder-segment is placedclose up to that of the other, then these two girder-segments may beconnected to be a quasi-continuous girder by tightening the boltsthrough their respective screw-holes on the connecting elements and thepre-embedded elements;

[0012] The aforesaid girder-segment may be a solid one or a hollow one(inclusive of empty chamber 3);

[0013] The aforesaid pre-embedded element is a concave-shape steelplate;

[0014] On the aforesaid concave-shape embedded element are disposed therolled-wire slant anchors for applying pre-stress;

[0015] Furthermore, on the aforesaid concave-shape embedded element forthe rolled-wire slant anchors also are disposed the horizontal anchorbar;

[0016] Additionally, by means of tightly pressing the concave shapeembedded elements in the girder top at connecting end of girder-segmentwith post-tensioned prestress reinforcing bar, these two adjacentgirder-segments will be connected more tightly and firmly;

[0017] The aforesaid girder-segment is a reinforced concrete girder;

[0018] The aforesaid girder-segment is a pestressed concrete girder;

[0019] The connection of the aforesaid connecting elements and embeddedelements also may employ the weld connection mode;

[0020] If the aforesaid girder-segment is of steel structure, theconnection mechanism may be further simplified, the connecting elementswill be simply connected respectively with the top plates or the bottomplates of these two or more than two steel structure girder-segmentswith bolts or by welding;

[0021] The upper and the lower connecting elements are respectivelyplaced at the inner sides of the upper top plate and the lower bottomplate in the steel girder chamber;

[0022] The aforesaid connecting elements may have various types, e.g.plate type (for connecting steel plates), block type, column type ortube type.

BRIEF DESCRIPTION OF APPENDED DRAWINGS

[0023]FIG. 1 is a schematic diagram of 2-span girder consisting of 2segments of the existing technology.

[0024]FIG. 2 is a structural schematic diagram of a guideway girderconnected by two concrete girder-segments in embodiment 1 of theinvention.

[0025]FIG. 3 is a schematic diagram of embedded element tightly pressedby post-tensioned reinforcing bar.

[0026]FIG. 4 is a plan view of FIG. 2.

[0027]FIG. 5 is a locally enlarged schematic diagram of the connectingportion in FIG. 4.

[0028]FIG. 6 is a schematic diagram of section along line A-A in FIG. 4.

[0029]FIG. 7 is a schematic diagram of section along line B-B in FIG. 4.

[0030]FIG. 8 is a structural schematic diagram of guideway girder formedby two connected steel girder-segments in embodiment 2 of the invention.

[0031]FIG. 9 is a schematic diagram of section along line C-C in FIG. 8.

[0032]FIG. 10 is schematic position diagram of steel connecting platedisposed in empty chamber of a steel girder.

[0033] In These Figures:

[0034]1, 2—girder segments;

[0035]3—empty chamber;

[0036]4—rolled-wire slant anchor;

[0037]5—post-tensioned pre-stressed reinforcing bar;

[0038]6—pre-embedded steel connecting element (pre-embedded element);

[0039]7—vertical anchoring nail;

[0040]8—connecting steel plate;

[0041]9—bolt;

[0042]10—horizontal anchor bar;

[0043]11, 12—steel structure girder-segments;

[0044]13—weld-joint place;

[0045]14—top plate;

[0046]15—bottom plate;

[0047]16—weld-joint place.

DESCRIPTION OF THE EMBODIMENTS

[0048]FIG. 2 is a schematic structural diagram of the guideway girderformed by two connected concrete girder-segments in embodiment 1 of theinvention. It is a horizontally hinge-jointed and approximate to acontinuous two-span guideway structure in vertical plane. Referring toFIGS. 3 to 7, embodiment 1 is a girder composed of concretegirder-segments 1 and 2. The girder-segment is a hollow girder with anempty chamber 3. In girder-segments are disposed the reinforcing bars.The connection structure between girder-segments 1 and 2 is formed byconcave-shape pre-embedded steel connecting element 6 (briefly calledpre-embedded element), vertical anchoring nails 7 are firmly connectedwith the pre-embedded element 6, connecting steel plate 8 and bolts 9.In embodiment 1, besides the vertical anchoring nail and horizontalanchor bar are designed, the rolled-wire slant anchor, which may applyslant pre-compressive force, is also specially designed in order toresist the horizontal force and the potential upward bending force actedbetween two girder-segments. As shown in FIGS. 4, 5 and 7, the abovestructure can ensure a reliable connection and a reliable forcetransferring between two girder-segments.

[0049] For further reliably ensuring the connection andforce-transferring between pre-embedded element and girder-segment 1 or2, the anchoring points of post-tensioned reinforcing bars 5 at theconnecting ends of girder-segments 1 and 2 may be moved upward to pressagainst the pre-embedded elements 6. As shown in FIG. 3 it is equivalentto applying a certain pre-compressive force on the pre-embedded element6.

[0050] The aforesaid pre-embedded elements 6 are respectively disposedin girder top and girder bottom at the connecting ends ofgirder-segments 1 and 2. The aforesaid connecting steel plates 8, in atotal of two pieces, are respectively disposed at intermediate positionof girder top and girder bottom at the connecting end of girder, thusgirder-segments 1 and 2 may be connected together with bolts 9 passingthrough the corresponding through-holes on pre-embedded elements 6 andconnecting steel plates 8. By so doing, the vertical spacing between twoconnecting steel plates 8 may be as large as possible and they are alsorespectively placed at the intermediate points along the horizontaldirection. Such a structure may ensure that the horizontalbending-rigidity is far less than that in the vertical plane, the formerless than 5% of the latter, and more ideally carrying out the connectionbetween two (or more than two) girder-segments in the vertical plane,approximate to continuous one as well as the connection between each twogirder-segments in horizontal plane still approximate to a hinge-jointof the original design conception. Namely, in vertical plane thegirder-segments are connected together to be a two-span or multi-spancontinuous girder and in horizontal plane each of them is still as asimply-supported girder. The results of calculation and practicalstructure measurement show that: in comparison of the structure of theinvention and that of an entirely continuous multi-span girder, theircharacteristics are quite close in the control of deformation caused bytemperature variation and dynamic load.

[0051] In connection mode, the connection between connecting steel plate8 and pre-embedded steel element 6 may utilize either weld connectionmode (weld line 12) or bolt 9 connection mode, the latter may adopt thefinish bolt connection mode or the high strength bolt connection mode.In case that the high strength bolt connection mode is adopted, bothcontact surfaces of the connecting steel plate 8 and concave-shapepre-embedded steel plate 6 have to be processed by sand blasting. Thesand blasting technology must meet the process requirement of thefriction surface for high strength bolt connection of steel structure.

[0052] In a certain degree twisting warping and bending deflection maybeexist between two adjacent girder-segments, especially between twogirder-segments with composite deformation, it will cause twopre-embedded steel plates 6 unable to be laid completely in a same planewith a result in connection that the connecting steel plates 8 cannotclosely contact with them, then the force-transferring will be affectedby it. In this case the shape of relevant connecting steel plate 8 maybe suitably rectified through flame heating in the center and watercooling during construction process to make it closely contact withthese two pre-embedded steel plates 6 of the girder-segments, namely, bymeans of the distorting deformation of steel plate 8 to adapt to thespace positioning of two adjacent girder-segments. This guarantees thatthe displacement of the accurately positioned girder-segments will notoccur because of the connection of girder-segments.

[0053] Due to sunshine and ambient temperature varitation, thetemperature difference between the girder top and the girder bottomsurfaces exist and will cause a hogback deformation of thegirder-segments. Under normal conditions, the temperature of girder topsurface is higher than that of the girder bottom surface, thus in mostcases, the hogback deformation is convex upward, its direction is justreverse to that of deflect deformation caused by the train dynamic load.If their magnitudes are equal, they will be balanced each other. Ofcourse, it is the most ideal status, so that an optimal comfort can beachieved when the train passes through the guideway line withhigh-speed. But in fact, the deflection is controlled by the bendingrigidity of girder itself and the temperature difference varies withtime, seasons and weather, therefore their magnitudes are alwaysdifferent in a certain degree. Because the connection structure of theinvention can tightly lock the connecting steel plates 8 under thecondition of a selected temperature variation range or a selected girderdeflection range, it can play the role of fine adjustment to the abovedifferences, controlling the deformation difference caused by variousfactors to a smaller range and achieve the purpose of optimal traincomfort.

[0054] Although other measures have been taken in the girder design, fora reinforced concrete girder, it is difficult to completely avoid theincrease of deflection caused by contraction and creep of concrete astime goes on. After the train has been operated for many years, if thedeflection caused by contraction and creep of concrete is large enoughto affect the requirements of train running, in this case, thefabrication method and the structure of the invention can be adopted.The connections between two adjacent girder-segments may be loosened andthen the relevant connecting steel plates 8 will not be tightly lockedagain until the hogging back of girder caused by temperature differenceis relatively big or the hogging back of girder is increased to acertain magnitude through application of external force. The objectivefor balancing the deflection caused by concrete and creep of concretemay be achieved by this method, and the guideway structure forhigh-speed train in its whole service life may be ensured to meet therequirement on dimensional tolerance for the operation of high-speedtraffic system.

[0055]FIG. 8 is a schematic structural diagram of the guideway girder inembodiment 2 of the invention, which is formed by two connected steelgirder-segments 11 and 12. Referring to FIG. 9, the guideway structuremay be further simplified, in this case two adjacent steel girdersegments are able to be connected only by directly connecting therelevant connecting steel plates 8 with their respective top plate 14and bottom plate 15 of the steel girder-segments 11 and 12 with bolt orusing the weld connection mode, thus the pre-embedded elements 6 for theconnection between the concrete girder-segments 1 and 2, as well as thecorresponding anchor elements such as vertical anchoring nails 7,horizontal anchor bars 10 and rolled-wire slant anchor 4 all may beomitted.

[0056] For the convenience of installation and no influence on theoperational space of train, the upper and the lower connecting steelplates 8 also may be respectively disposed at the inner side of topplate 14 and bottom plate 15 of the empty chamber 3 of steelgirder-segment as shown in FIG. 10.

[0057] Synthesizing above description, the improved technical effects ofthe invention are as follows:

[0058] 1. A quite difficult technical problem in respect of thefabrication, transportation and installation of the big and heavymulti-span guideway girder may be conquered and the construction cost ofmodem high-speed track-bound transportation, especially that of maglevguideway may be quite greatly saved, because each of girder-segments ofguideway may be pre-fabricated, processed, transported, installed andaccurately positioned as simply-supported girders and then two or morethan two girder-segments may be connected together to be a two-span ormulti-span quasi-continuous guideway girder with the connectionmechanism.

[0059] 2. The connection mechanism of girder-segments of the inventionis one composed of pre-embedded elements respectively disposed on girdertop and girder bottom of girder-segment's connecting ends, or composedof two connecting steel plates respectively disposed on girder top andgirder bottom of girder-segment's connecting ends, as a result thevertical spacing between the two connecting plates can be as large aspossible and in lateral plane they are respectively placed atintermediate positions of girder-segment's connecting ends, able toensure the bending rigidity of the connection in lateral plane is farsmaller than that in vertical plane. In other words, in vertical planethe girder-segments are connected together to be a two-span ormulti-span quasi-continuous girder but in horizontal plane each ofgirder-segments is still kept as a simply-supported girder connectedwith other adjacent ones;

[0060] 3. The connection mechanism of the invention relatively is simpleand able to provide a convenient condition for repair and maintenance infuture.

[0061] The above only exemplifies the optimal embodiments of theinvention and the connection of a two-span girder-segments is describedas an example. That does not mean that the structure of the inventionmay be popularized to the connection of multi-span girder-segments. Itcannot be understood that the present invention is limited to theseexemplified embodiments and relevant descriptions. Any simplemodifications in the application of the conception and the structure ofthe present invention belong to the scope of protection of the presentinvention.

We claim:
 1. A guideway structure for high-speed track-boundtransportation composed of two or more than two girder-segments (1) and(2). The structure of the guideway is characteristic of: At theintermediate positions on the girder top and the girder bottom of theconnecting ends of the said girder-segments (1) and (2) are all disposedthe pre-embedded steel elements (6) and some anchoring nails (7) usedfor ensuring the pre-embedded steel elements (6) to be reliablyconnected with the concrete of girder-segments, after the relevantconnecting ends of the two adjacent girder-segments are placed closely,they may be connected together to form a two-span quasi-continuousgirder by tightening a plurality of bolts through their respectivethrough hole on the connecting elements (8) and on the pre-embeddedelements.
 2. The guideway structure for high-speed track-boundtransportation of claim 1, characterized in that the saidgirder-segments (1) and (2) may be solid girder-segments or hollowgirder-segments.
 3. The guideway structure for high-speed track-boundtransportation of claim 1, characterized in that the said pre-embeddedelements (6) are concave-shape steel plates.
 4. The guideway structurefor high-speed track-bound transportation of claim 3, characterized inthat on said concave-shape pre-embedded elements (6) are also disposedrolled-wire slant anchors (4) for applying the prestress.
 5. Theguideway structure for high-speed track-bound transportation of claim 4,characterized in that on said concave-shape pre-embedded elements (6)with rolled-wire slant anchors (4) thereon also are disposed horizontalanchor bars (10).
 6. The guideway structure for high-speed track-boundtransportation of claim 5, characterized in that the said concave-shapepre-embedded elements (6) respectively placed on the girder tops ofconnecting ends of the said girder-segments (1) and (2) are pressedtightly by post-tensioned prestress reinforcing bar (5) in order thatthe said pre-embedded elements (6) can be further firmly connectedrespectively with said girder-segments.
 7. The guideway structure forhigh-speed track-bound transportation of claim 1, characterized in thatthe said girder-segment is a reinforced concrete girder.
 8. The guidewaystructure for high-speed track-bound transportation of claim 1,characterized in that the said girder-segment is a prestressedreinforced concrete girder.
 9. The guideway structure for high-speedtrack-bound transportation of claim 1, characterized in that the weldconnection mode may also be used for the connection of the saidconnecting element (8) and the said pre-embedded element (6).
 10. Aguideway structure for high-speed track-bound transportation composed oftwo or more than two girder-segments (1) and (2) is that: The top plates(14) of their respective girder-segment or the bottom plates (15) oftheir respective girder-segment may be connected together by connectingelement (8) directly in the bolt connection mode or the weld connectionmode.
 11. The guideway structure for high-speed track-boundtransportation of claim 10, characterized in that the upper and thelower connecting element (8) is respectively placed at the inner side ofthe top plate (14) and the bottom plate (15) of the empty chamber (3) ofthe steel girder.
 12. The guideway structure for high-speed track-boundtransportation of claim 10, characterized in that the said connectingelement (8) may have various types, such as plate type, block type,column type and pipe type.